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Pharmaceutical Secondary Standard; Certified Reference Material

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2,4-Diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine, NSC 106568
Empirical Formula (Hill Notation):
CAS Number:
Molecular Weight:
Beilstein/REAXYS Number:
EC Number:
MDL number:
PubChem Substance ID:


certified reference material
pharmaceutical secondary standard

Quality Level


traceable to BP 344
traceable to Ph. Eur. T220000
traceable to USP 1692505

API family



current certificate can be downloaded


HPLC: suitable
gas chromatography (GC): suitable


pharmaceutical (small molecule)



storage temp.


SMILES string




InChI key


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General description

Certified pharmaceutical secondary standards for application in quality control provide pharma laboratories and manufacturers with a convenient and cost-effective alternative to pharmacopeia primary standards. Trimethoprim is a synthetic antibacterial agent active in vitro against most aerobic gram-negative and gram-positive bacteria. Its mode of action involves inhibition of dihydrofolate reductase, an enzyme involved in catalyzing the reduction of dihydrofolate to tetrahydrofolate in both microbial and eukaryotic cells.


These Secondary Standards are qualified as Certified Reference Materials. These are suitable for use in several analytical applications including but not limited to pharma release testing, pharma method development for qualitative and quantitative analyses, food and beverage quality control testing, and other calibration requirements.
Trimethoprim may be used as a pharmaceutical reference standard for the determination of the analyte in pharmaceutical formulations by chromatography and visible and UV spectrophotometry.
Primarily used as an antibacterial agent. Dihydrofolate reductase inhibitor with selectivity for the prokaryote enzyme.

Analysis Note

These secondary standards offer multi-traceability to the USP, EP (PhEur) and BP primary standards, where they are available.

Other Notes

This Certified Reference Material (CRM) is produced and certified in accordance with ISO 17034 and ISO/IEC 17025. All information regarding the use of this CRM can be found on the certificate of analysis.


To see an example of a Certificate of Analysis for this material enter LRAA7172 in the slot below. This is an example certificate only and may not be the lot that you receive.

Recommended products

Find a digital Reference Material for this product available on our online platform ChemisTwin® for NMR. You can use this digital equivalent on ChemisTwin® for your sample identity confirmation and compound quantification (with digital external standard). An NMR spectrum of this substance can be viewed and an online comparison against your sample can be performed with a few mouseclicks. Learn more here and start your free trial.


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Hazard Classifications

Acute Tox. 4 Oral - Repr. 2

Storage Class

11 - Combustible Solids




Not applicable


Not applicable

Certificates of Analysis (COA)

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Lot and Batch Numbers can be found on a product's label following the words 'Lot' or 'Batch'.

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Customers Also Viewed

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Determination of sulfamethoxazole and trimethoprim in pharmaceuticals by visible and UV spectrophotometry
Shamsa F and Amani L
Iranian Journal of Pharmaceutical Research : IJPR, 537(1-2), 31-36 (2010)
Simultaneous LC determination of trimethoprim and sulphamethoxazole in pharmaceutical formulations
Akay C and Ozkan SA
Journal of Pharmaceutical and Biomedical Analysis, 30(4), 1207-1213 (2002)
Comparison of trimethoprim molecularly imprinted polymers in bulk and in sphere as the sorbent for solid-phase extraction and extraction of trimethoprim from human urine and pharmaceutical tablet and their determination by high-performance liquid chromatography
Hu SG, et al.
Analytica Chimica Acta, 537(1-2), 215-222 (2005)
Trimethoprim resistance.
Huovinen P
Antimicrobial Agents and Chemotherapy, 31(10), 1451-1456 (1987)
Ivan Senta et al.
Water research, 47(2), 705-714 (2012-11-29)
Comprehensive study on the occurrence and fate of several classes of antimicrobials, including sulfonamides, trimethoprim, fluoroquinolones and macrolides, in Croatian municipal wastewaters was performed using an integrated approach, which comprised analysis of both dissolved and particulate fractions. A nation-wide screening

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